NITROGEN 



237 



NORTHERN 



Nitrogen, (n I'tro-jen). [Nitre, q.v.; Gk. 

 gennao, I produce.] N"': a colourless, taste- 

 less, inodorous, neutral gas forming one-fifth 

 in volume of atmospheric air; also called 

 Azote. The indifference of N. causes easy 

 decomposition, and hence the explosive 

 power of salts of nitrogen. Protoxide of 

 jy.= Laughing Gas, q.v. 



Nitrosion, (ni-tro'si-on). [Nitrogen, q.v.]= 

 NCKj: combines with metals of the alkalies 

 to form nitrites. 



Nitrosyl, (ni'tro-sil). [Nitrogen, q.v.] NO= 

 Nitric oxide. 



Nitrous, (ni'trus). [Nitrogen, q.v.] N. acid 

 =NoO3: now called N. anhydride. N. ether 

 =(C~ 2 H 5 )N0 2 = Ethyl Nitrite: a yellow, 

 odorous liquid. N. oo;ide=:Laughiug gas: 

 NoO. 



Nifroxyl, (ni-troka'il). [Nitrogen and 

 to/gen. ]=NO2=Peroxide of nitrogen. 



Noah's dove. v. Columba Noachi. 



Nobili's. N. pile: a thermo-electric battery 

 composed of a number of couples of bismuth 

 and antimony; v. Thermo-electricity. N. 

 rings: coloured rings formed by decom- 

 position of a copper or lead salt in circles 

 round the negative pole of a galvanic 

 battery. 



Noble Metals. Gold, silver, mercury, platii- 

 num, &c., which cannot decompose water, 

 and do not readily unite with oxygen: occur 

 mostly in a native condition. 



Noctiluca, (nok-ti-lu'ka). [L. node, by night; 

 luceo, I shine.] Phosphorescent protozoa, 

 consisting essentially of vacuolated proto- 

 plasm, forming a nearly spherical animalcule. 



Noctilucin, (nok-ti-lu'sin). [Noctiluca, q.v.] 

 The semi-fluid substance which, in phos- 

 phorescent animals, causes light. 



Noctuae, (nok'tu-G). [The Latin word.] 

 Night-flying moths : a division of Lepi- 

 doptera. 



Nocturnal, (nok-tur'nal). N. animals: mice, 

 rats, bats, moles, owls, goat-suckers, &c., 

 usually grey and v \ 

 inconspicuous. \'t ' 



Nocturni, (nok- 

 tur'ni)=Noctuse, 



Nodal, (no'dal). 



[Nodes, q. v.] N. 



lines: the lines 



of rest in a 



vibrating plate 



or membrane. 

 Noddy, (nod'di)= 



Booby, q.v. 

 Nodes, (nodz). 1. Points of rest in a vibrating 



string or rod, or in a column, 



of aii\ 2. Points in which 



the orbit of any heavenly 



body intercepts the ecliptic 



or orbit of the earth. 

 Noise. Sudden or discor- 

 dant sounds. cf> Music, v. 



Sound. Node. 



Nolanaceae, (no-la-na'se-u). [L. nola, little 



bell.] Nolanads: S. American herbs, with 



showy flowers, belonging to Echiales. 



Nomadae, (nom'a-de). [L. nomas, wandering.] 



=Cuckoo-bees=Naked-bees, q.v. 

 Nomenclature, ( n5'men-kla-tur ). [Nomen- 



clatura, the Latin word.] The vocabulary 



of any science, &c. v. Tables. 

 Nonagesimal, (non-a-jes'i-mal). [L. nona- 



gesimus, ninetieth.] Belonging to the 



number 90; iised for the English system 



of arc measurements, in which a right 



angle is equal to 90 degrees. 

 Nonagon, (non'a-gon). [L. nonus, ninth; Gk. 



gonia, angle.] Generally: a plane figure 



having nine angles, especially a regular 



plane figure bounded by nine equal sides. 

 Nonane, (non'an) = Nonyl hydride = CgH 



v. Paraffin. 

 Nontronite, (non'tro-nit). [Nontron, in 



France.] A mineral, chiefly hydrated sili- 

 cate of iron. 

 Non-conductors of heat, electricity: shellac, 



india-rubber, sulphur, glass, silk, &c. 

 Nonylene, ( non'i-len ) = CgHjg = Elsene: a 



hydrocarbon of the oleflne series obtained 



from lime soap. 



Nonylic acid. C 9 H 18 O 2 =Pelargonic acid. 

 Noon, (non). [Non, the A.-S. word.] Twelve 



o'clock at mid-day; the commencement of 



the astronomical day. Apparent N.: when 



the centre of the sun is on the meridian. 



Mean N.: when the mean sun is on the 



meridian. 

 Nopal, (no'pal). [A corruption of the native 



word.]:=0puntia cochinillifera: found on the 



shores of Mediterranean : the only cactus on 



which the cochineal insect feeds. 

 Nordhausen sulphuric acid. [N., a town in 



Saxony.]=^. oil of virzoZ=Concentrated 



sulphuric acid. 

 Norfolk Island pine. Araucaria excelsa: a 



very large tree, about 200 ft. in height; also 



called Eutassa. 

 Norium, (n5'ri-um). No: an hypothetical 



metal. 

 Nonna, (nor'ma). [The Latin name.]=The 



Rule: an unimportant constellation. 

 Normal, (nor'mal). [L. norma, a rule.] 1. 



Perpendicular. 2. A straight line which is 



perpendicular to a curve. 

 Normal organic acid = H(CnH2n-iO)O. v. 



Organic acids. 



Norman arch. Semicircular: found in build- 

 ings of the Norman /\ 



period, cf. Gothic arch. / 

 Nortes, (nor'tez)=/ 



Northers : dry, cold 



winds, blowing from" 



September to March, 



in the Gulf of Mexico. 

 North polar distance, 



of a heavenly body 



from the N. celestial 



pole. 

 Northern, (nor'THern). 



[North.] JV. crown = 



Corona Borealis. N. Norman arch. 



ZirM:=Aurora-borealis, q.v. N. hemisphere: 



the half of the globe containing Europe, N. 



America, &c. N. pole=S. pole of the French : 



the pole of the N. hemisphere. N. 



